<html>
  <head>
    <style type="text/css">
      .square {
        position: absolute;
        top: 0;
        left: 0;
        width: 200px;
        height: 100px;
        background-color: red;
        animation-name: z-spin;
        animation-duration: 5s;
        animation-iteration-count: infinite;
        animation-timing-function: linear;
      }

      @keyframes z-spin {
        0%    { transform: rotateZ(0deg); }
        100%  { transform: rotateZ(360deg); }
      }
    </style>
  </head>
  <body >
      <div class="square"></div>
  </body>
</html>
